The Mercedes S 400d 340hp (W222 - 2017 - 2019) produces 340bhp and 700Nm in standard form. Our Stage 1 ECU tuning file raises output to 410bhp and 840Nm, a gain of 70bhp and 140Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.